Creating a handler for a link popup/modal

I’m using react-quill@1.0.0 in my React component, and would like to customize the “link” button so that it displays a popup/modal in which the user can paste the link and the link text.

So far this is what I’ve got:

var TextEditor = React.createClass({

    getInitialState: function () {
        return {
            text: this.props.initialData
        }
    },

    onTextChange: function (value) {
        this.setState({ text: value });
    },

    modules: {
        handlers: {
            // handlers object will be merged with default handlers object
            'link': function(value) {
                if (value) {
                    var href = prompt('Enter the URL');
                    this.quill.format('link', href);
                } else {
                    this.quill.format('link', false);
                }
            }
        }
    },

    formats: [
        'header',
        'bold', 'italic', 'underline', 'strike', 'blockquote',
        'list', 'bullet', 'indent',
        'link',
    ],

    render: function () {
        return (
            <ReactQuill theme="snow"
                        value={this.state.text}
                        onChange={this.onTextChange}
                        modules={this.modules}
                        formats={this.formats} />
        )
    }

});
export default TextEditor;

The error message I’m getting is that it can’t find the “handlers” module. Any ideas anyone on how to get this working?